Frequent Questions about NFPA 13 vs. 13RI've been asked a handful of times in early project planning phases on whether NFPA 13R would be allowed in lieu of NFPA 13 for a project. In short, the two standards have very different objectives and as a result require very different means.

While those who ask are generally looking for ways to save on construction for the project, the differences are important and worth discussing early in a project.

Designed for Different PurposesIt's important to note that NFPA 13R systems are designed primarily with the intent for life safety (extending the amount of time occupants have to escape a burning building). It's stated purpose is to additional "prevent flashover in the room of fire origin, where sprinklered" (NFPA 13R 2019 1.2.2).

Unlike NFPA 13, NFPA 13R works to make the installation of the sprinkler system more affordable and accessible for residential occupancies by targeting the areas of highest fire risk to life safety with sprinkler systems. Swapping NFPA 13 and NFPA 13R is not simply a one-for-one exchange, as their goals are overall quite different.

​Summary of DifferencesHere's the summary of differences I use between NFPA 13, 13R, and 13D as a downloadable PDF (at the bottom of this page). References to the building code are to the International Building Code, as it's typically the most prevalent used in the US.

As always, there's far more detail to many of these requirements than can be summarized in two pages - so be sure to use the supplied section references to gather more information on specifics for your project.

CODE PLANNING

-

NFPA 13

NFPA 13R

NFPA 13D

Objective

Life Safety+ Property Protection[NPFA 13 2002-2019 1.2.1]

Life Safety Only[NFPA 13R 2002-2019 1.2]

Life Safety Only[NFPA 13D 2002-2019 1.2.1]

Considered "Fully-Sprinklered" ?

Yes[IBC ref. section 903.1.1 as fully-sprinklered]

No[IBC references 'buildings equipped with a sprinkler system per 903.3.1.1, which is an NFPA 13 system]

No

Building Height Increases Permitted

Yes[IBC Table 504]

Only for R-Occupancy[IBC Table 504]

No​

Permitted in One & Two-Family, or Group R-3 & R-4 Condition 1 and Townhouse R-Occupancies?

This glosses over one big requirement the IBC area increase. The building maybe perfect for NFPA 13R but the area has increased and the building now requires a NFPA 13 system.

Reply

Joe

9/23/2018 03:40:20 pm

Well said - expanding on an existing building with an NFPA 13R system can require a formal fire wall separating what becomes to separate buildings. I could probably break this out a little better.

The trouble I often see with the discussion of NFPA 13R vs. NFPA 13 is that in a 'design-build' scenario the sprinkler contractor is the only one asked if NFPA 13R can be used while the architect may be making different assumptions when making egress and code decisions.